Intro Flashcards
What is the definition of Biological Evolution?
The change over time in the proportions of individual organisms differing genetically in one or more traits
What are Darwin’s Postulates of Adaptation?
There is variation
Variation is heritable
Not all individuals can survive/reproduce
Some of the variation affects survival and/or reproduction
Traits which enhance survival and/or reproduction will become more common
What are mutation and selection? Are they random?
Mutation generates variation at random with no foresight or purpose
Selection filters the variation. It is not random, but has no foresight
What was the real time example of evolution provided, and what factors does it use?
HIV/AIDS
Evolution of virulance and drug resistance
Divergence from common ancestor
What does the HIV virus use to insert into the host cell? What does it use on the host cell?
The virus has a Gp120 protein which is used for attachment on the CD4 host receptor
What do HIV treatment drugs target? Provide an example of drug
AZT targets reverse transcriptase
How does the virus adapt to the drug treatment? Relate to Darwin’s Postulates
Variation - Reverse transcriptase makes errors and causes mutations
Variation is heritable - mutation is incorporated into all daughter virions
Not all individuals reproduce - AZT blocks reproduction in most viruses
Some variation affects survival - mutants resistant to AZT reproduce more
Traits which enhance survival will become more common - AZT resistance evolves within host
What other general type of animal is HIV found in?
Many different species of monkey
How does the virion avoid host immune response?
Changes the gp120 surface protein to evade attack
What are the assumptions of Hardy Weinberg Equilibrium?
Large population with no genetic drift No mutation No selection No migration Random mating
